Place a video on a still picture of a monitor
Visit the following site for instructions: https://www.maketecheasier.com/blender-3d-virtual-video-screens
Or, if you have Import Images as Planes add-on, you may do this in BI, too, as your video/image is mapped correctly after it's imported. It's possible to model such "a screen" and join it with CTRL+J. 

To have audio, do as follows:


Extract audio and video from your clip to have two separate files
Follow the procedure given in the tutorial using the video without sound.
In VSE combine it with the extracted audio